Field conditions such as those found on a battlefield or in some types of remote environments most often do not support the use or presence of laboratory facilities or the type of equipment used therein, making it difficult to test for and identify the presence of microbial pathogens or other analytes of interest in a sample to be investigated such as blood. A durable, yet disposable, self-contained assay system is needed for identification of the presence of microbial pathogens or other analytes of interest in field conditions.